Alberto Verrier Hernández

xln23 from Streptomyces chattanoogensis UAH23 Encodes a Putative Enzyme with Separate Xylanase and Arabinofuranosidase Catalytic Domains

The xylanase gene xysA of Streptomyces halstedii JM8 was used to isolate a DNA fragment from a gene library of Pstf-digested chromosomal DNA of the lignocellulolytic actinomycete Streptomyces chattanoogensis CECT-3336. Nucleotide sequence analysis revealed a gene (xln23) encoding a bifunctional multi-modular enzyme bearing two independent xylanase and a-L-arabinofuranosidase domains separated by a Ser/Gly-rich linker. The N terminus of the predicted protein showed high homology to family F xylanases. The C terminus was homologous to amino acid sequences found in enzymes included in the glycosyl hydrolase family 62 and, in particular, to those of a-L-arabinofuranosidase AbsB from Streptomyces livi-dans. PCR and RT-PCR experiments showed that the nucleotide sequences corresponding to each domain are arranged as expected on the chromosomal DNA and that they are cotranscribed. To our knowledge, this is the first description of xylanase and arabinofuranosidase domains in a same open reading frame.

Nueva prótesis de maleovestibulopexia. Diseño y análisis experimental en un modelo computarizado 3D basado en elementos finitos

INTRODUCTION AND OBJECTIVE Many designs of prostheses are available for middle ear surgery. In this study we propose a design for a new prosthesis, which optimises mechanical performance in the human middle ear and improves some deficiencies in the prostheses currently available. Our objective was to design and assess the theoretical acoustic-mechanical behaviour of this new total ossicular replacement prosthesis. METHODS The design of this new prosthesis was based on an animal model (an iguana). For the modelling and mechanical analysis of the new prosthesis, we used a dynamic 3D computer model of the human middle ear, based on the finite elements method (FEM). RESULTS The new malleovestibulopexy prosthesis design demonstrates an acoustical-mechanical performance similar to that of the healthy human middle ear. This new design also has additional advantages, such as ease of implantation and stability in the middle ear. CONCLUSIONS This study shows that computer simulation can be used to design and optimise the vibroacoustic characteristics of middle ear implants and demonstrates the effectiveness of a new malleovestibulopexy prosthesis in reconstructing the ossicular chain.

OK-432 como tratamiento del linfangioma cervicofacial en el adulto☆

El tratamiento del linfangioma cervicofacial esta cambiando en los ultimos anos. La solucion de OK-432 se presenta como un tratamiento relativamente seguro y efectivo para los pacientes de cualquier edad. La inyeccion intraquistica del OK-432 produce una reaccion inflamatoria local que resuelve la lesion. El aspecto estetico es excelente, ya que no deja lesiones cutaneas en el lugar de la inyeccion, a diferencia de otros agentes esclerosantes. Por ello se puede considerar el tratamiento de eleccion, especialmente en casos en que el tratamiento quirurgico puede producir serias secuelas funcionales o esteticas.

[OK-432 therapy for cervicofacial lymphangioma in adults].

The treatment of cervicofacial lymphangiomas has been changing in recent years. OK-432 appears to be a relatively safe and effective treatment option for patients of all ages. An intracystic injection of OK-432 produces a local inflammatory reaction, leading to resolution of the lesion. Cosmetically, the outcome is excellent, leaving no lesions on the skin at the injection site, unlike other sclerosing agents. It may thus be considered as the treatment of choice, especially in cases where surgical treatment is associated with the possibility of serious functional or cosmetic side effects.

Análisis experimental mediante vibrometría láser doppler en huesos temporales de cadáver fresco de una nueva prótesis de maleovestibulopexia

INTRODUCTION AND OBJECTIVES One of the problems with total ossicular replacement prostheses is their stability. Prosthesis dislocations and extrusions are common in middle ear surgery. This is due to variations in endo-tympanic pressure as well as design defects. The design of this new prosthesis reduces this problem by being joined directly to the malleus handle. The aim of this study is to confirm adequate acoustic-mechanical behaviour in fresh cadaver middle ear of a new total ossicular replacement prosthesis, designed using the finite elements method. METHODS Using the doppler vibrometer laser, we analysed the acoustic-mechanical behaviour of a new total ossicular replacement prosthesis in the human middle ear using 10 temporal bones from fresh cadavers. RESULTS The transfer function of the ears in which we implanted the new prosthesis was superimposed over the non-manipulated ear. This suggests optimum acoustic-mechanical behaviour. CONCLUSIONS The titanium prosthesis analysed in this study demonstrated optimum acoustic-mechanical behaviour. Together with its ease of implantation and post-surgical stability, these factors make it a prosthesis to be kept in mind in ossicular reconstruction.